EAPSI: Improving the Safety and Durability of Cable-supported Bridges in Wind

EAPSI：提高缆索支撑桥梁在风中的安全性和耐久性

• 批准号: 1514876
• 负责人: Maria Gibbs
• 金额: $ 0.01万
• 依托单位: Gibbs Maria M
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-06-01 至 2016-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1514876&HistoricalAwards=false
• 关键词: EAPSI; Improving; Safety; Durability; Cable

Long span cable-supported footbridges are particularly vulnerable to wind-induced failure due to their light and flexible nature. This project seeks to identify key characteristics of a standardized suspension footbridge in order to predict how the structure will respond during a wind event. This research will be conducted in collaboration with Dr. Ge Yaojun, a noted wind engineering expert. State of the art wind tunnel facilities at Tongji University in Shanghai will afford the unique opportunity to perform full-scale deck section wind tunnel experiments which will be used to assess safety of this type of bridge in the event of a wind storm and provide guidelines for span limits and wind mitigation strategies. The dynamic characteristics of these footbridges are widely unknown and no previous experimental investigation of the structures under wind loading has been performed. Discovering their fundamental characteristics will lay the groundwork for the structures to serve as a test bed for the investigation of non-linear features in the behavior of flexible bridge structures.Developing a predictive wind analysis framework and ultimately a design standard which incorporates wind vulnerability for flexible footbridges hinges on the identification of bridge deck aerodynamic characteristics. The framework will incorporate a numerical model built in ANSYS which uses flutter and buffeting forces reliant on section model wind tunnel tests. Bridge deck motion will be modeled with two degrees of freedom in the vertical and rotational directions. These wind-induced loads will be modeled using both traditional and updated schemes. These schemes require aerodynamic coefficients and aerodynamic and aeroelastic transfer functions measured using section model tests in the wind tunnel Access to full scale monitoring data from a number of existing footbridges which incorporate this standard deck detail will allow for an unprecedented look at how one can model these types of bridges in a hybrid wind tunnel/computational approach and also the prospect of capturing any scaling error that may distort response predictions compared to the observed behavior of the actual structure under wind loads. This NSF EAPSI award support the research of a U.S. graduate student and is funded in collaboration with the Chinese Ministry of Science and Technology.

大跨度缆索支撑人行桥由于其重量轻且灵活，特别容易受到风引起的破坏。该项目旨在确定标准化悬索人行桥的关键特征，以预测该结构在风事件期间将如何响应。该研究将与著名风工程专家葛耀军博士合作进行。上海同济大学最先进的风洞设施将为进行全尺寸桥面截面风洞实验提供独特的机会，该实验将用于评估此类桥梁在暴风雨情况下的安全性，并为跨度限制和防风策略提供指导。这些人行桥的动力特性广为人知，之前也没有对风荷载下的结构进行过实验研究。发现它们的基本特征将为这些结构作为研究柔性桥梁结构行为非线性特征的试验台奠定基础。开发预测风分析框架并最终制定包含柔性人行桥风脆弱性的设计标准取决于桥面空气动力学特性的识别。该框架将包含在 ANSYS 中构建的数值模型，该模型使用依赖于截面模型风洞测试的颤振和抖振力。桥面运动将以垂直和旋转方向的两个自由度进行建模。这些风致荷载将使用传统方案和更新方案进行建模。这些方案需要在风洞中使用截面模型测试测量空气动力系数以及空气动力和气动弹性传递函数。从许多现有的人行天桥（包含此标准桥面细节）获取全尺寸监测数据，将允许人们以前所未有的方式了解如何在混合风洞/计算方法中对这些类型的桥梁进行建模，并有望捕获任何可能扭曲响应预测的比例误差。 观察实际结构在风荷载下的行为。该 NSF EAPSI 奖项支持美国研究生的研究，并由与中国科学技术部合作资助。